The Bush administration says if an H5N1 bird flu pandemic begins, there will be no point in closing U.S. borders because that would only slow - and not stop - the deadly disease from spreading throughout the country.

A draft of a plan to be formally released by the White House Wednesday says closing the border would have significant negative consequences for the economy and foreign affairs.

The plan lays out specific tasks for each federal government agency and has recommendations for schools, businesses, health care professionals and ordinary citizens in case a pandemic occurs.

The document forecasts that 40 percent of the workforce would be absent during the height of the pandemic, and up to nearly two million Americans could die from the virus.

The H5N1 avian virus has spread out of Asia, across Europe and into many parts of Africa. It does not easily infect humans, but since 2003 it has sickened some 200 people, mostly in Asia, and more than 100 have died from the deadly disease.